Waterproofing composition and process



Patented June 9, 1936 I UNITED STATES WATERPROOFING COMPOSITION AND PROCESS John R. Hubbard, Gowanda, N. Y., assignor to Peter Cooper Corporations, Gowanda, N. Y.

No Drawing. Application July 10, 1934,

Serial No. 734,528

Claims. (01. ill- 68) This invention relates to the'manufacture of papers, fabrics or other webs having a coat or film applied thereto which includes a protein adhesive, and particularly to render the film or adhesive material water-fast.

Most sizing materials for wall papers include protein materials, such as glue, casein, and the like, and these materials are usually mixed with pulp colors and the mixture is applied to the paper by printing or other-means. In the case of fabrics or other webs, the sizing material may be applied to the web in other ways. In accordance with my invention, I-treat the sized webs either immediately after-the application of the sizing material or after the sizing material has dried, with a composition which acts on the protein substances of the sizing material to render the same water-fast. Wall papers of this kind have heretofore been made water-fast, either by applying over the printed coating a film of varnish or other water-proof material, or by treating the paper with formaldehyde. The first of these treatments adds materially to the expense of the paper, and frequently the water-proof film results in changes in the appearance of the paper. The treatment of the paper with formaldehyde is very objection- .able because of the fact that formaldehyde gas is liberated during the treatment of the paper, and particularlyduring the drying thereof and passes into all parts of the building in which the paper is made, causing annoyance and possible injury to workers and also afiecting the viscosity of color solutions which are mixed and ready for use in printing, and causing other damage in the factory. Furthermore, after suchpapers are sold, additional formaldehyde gas is sometimes liberated after the paper has been applied to a wall. It is, consequently, very desirable bothfrom the manu facturers and the-user's standpoint to avoid the use of formaldehyde gas in the water-proofing of wall papers or other papers used in the interior of buildings.

The objects of this invention are to provide means for water-proofing papers and fabrics coated or impregnated with protein sizing ma-.

terials and which will effectively render the sizing material water-proof, and which will not give off any objectionable odors or gases, either during the process of manufacture of such papers or fabrics or during the use thereof; also to improve the making of paper or fabric articles water-fast in other respects hereinafter specified.

In the treatment of paper or fabrics having sizing material including a protein substance incorporated therein, it is desirable that the water-- proofing of such protein material be effected rapidly, so as to facilitate the manufacture of such materials, and also in the case of paper to avoid the disintegration or weakening of the paper by the moisture in the water-proofing composition. 5

It is known that certain salts of aluminum have a hardening action on certain protein materials, but I have found that a satisfactory water-proofing action can best be obtained by the use of aluminum salts of inorganic acids or by alums, and with such salts, the efiiciency of their reaction depends upon the proper control of the pH value of the solution. It is essential to a satis-' factory water-proofing of protein materials that a somewhat basic aluminum salt solution as differentiated from the normal aluminum salt solution should enter or be formed in the pores of the prctein material, as well as become deposited upon the surface thereof. In order to obtain the most satisfactory results, these salts should react with the protein material or certain ingredients thereof, and form a basic aluminum oxide, or

aluminum hydroxide, which, upon drying, forms a basic salt of aluminum, which is probably combined with or linked to the protein material.

Such a basic salt combination is relatively insoluble in water or highly water-resistant, and consequently, wall paper coated or impregnated with a sizing containing such protein materials will become water-resistant or washable, if treated aluminum salt of an inorganic acid", as herein- .after used, is intended to include alum.

In accordance with my process, I make a solution of an aluminum salt of an inorganic acid or of an alum. This solution may then be modified to render the same less acid, or in other words, to raise its pH value, to a point which must not be so high as to cause aluminum hydroxide to be formed in the solution, which can be detected by the forming of a precipitate or cloudiness in the solution. Such precipitated aluminum hydroxide, if present only in small quantities, in some cases is not objectionable,- since it becomes depositedupon the surface of the protein ma' terial, and thus has some water-proofing action. Such precipitate'does not adequately penetrate the pores of the protein material, andfurther- In the alum, the aluminum con- 35 more, when the material under treatment includes dark colors, the precipitated aluminum hydroxide will form white spots on such colors. For these reasons, it is preferable to have the solution substantially clear and free from precipitate.

I have also found that if the pH value of the solution is too low, 1. e., that the solution is too strongly acid, the acidity prevents the formation of a basic aluminum hydroxide of such a nature as to give the protein material the desired waterresisting eifect. Generally speaking, the solution should be modified by addition of a suitable alkali so as to raise the pH value of the solution in the range of pH 3.5 to 4.6. With aluminum sulfate, the pH value should not be lower than 3.9 to obtain the best results. In most cases, the most satisfactory results are obtained with a solution of pH 4.1 to 4.2. pH values above 4.6 tend to give inferior water-proofing qualities. pH values of aluminumsalt solutions of inorganic acids more neutral than a pH of 4.6'obtained by adding buffer salts in conjunction with alkali materials give less satisfactory results than similar solutions at a pH of 4.0 to 4.2.

Any suitable alkali materials may be used to raise the pH value of the aluminum salt solution. Soda ash or sodium hydroxide are entirely satisfactory for this purpose, and also have the advantage of being readily available commercially and inexpensive. Borax, sodium acetate, or various other alkaline salts may, how ever, be used. Ammonia can also be employed, but is less desirable for practical factory operation. When my composition is used in connection with wall paper, it must, of course, be borne in mind that no ingredients can ordinarily be used which would change the color of the paper, either through chemical reaction with the colors, or due to a physical change due to a colored reagent solution. For this latter reason, only colorless solutions should be used.

It is essential to the commercial manufacture of wall paper that the water-proofing action take place quickly, for reasons already stated. I have found that the water-proofing action of basic aluminum salts of inorganic acids can be materially accelerated and also a more uniform deposit and deeper penetration of the protein film may be obtained, if certain materials are used .in the solution. Among these materials that may be used in this manner, and which are hereinafter referred to as accelerating agents, the following are given as examples: borax, sodium, ammonium or potassium acetates, sodium, ammonium or potassium oxalates, or tartrates, sodium chloride, and also sulfonated phenols. Since some of these materials have an alkali reaction, theycan be used for the twofold purpose of raising the pH value of the solution and at the same time imparting to the solu-- tion the properties ofspeeding-up the waterproofing of the protein material, and providing for a better penetration of the film of protein material.

In the carrying out of my invention, the waterproofing solutions may be applied to the sized web in any suitable or desired manner. For example, if the solution is made of such strength as to be approximately a 10% solution of a somewhat basic aluminum salt of an inorganic acid, a single application of the solution to the work is ordinarily sufficient. The solution may thus be applied to the web by means of rollers having their surfaces wetted with the solution and contacting with one or both surfaces of the web, or the solutions may be sprayed on the web. In the case of a web coated on one side only with the protein sizing material, it is also possible to apply my water-proofing solution to the opposite side thereof with the addition of suitable penetrant materials to the solution, so that the waterproofing solution penetrates through the Web to the sizing film to be treated. The web may also be completely immersed in the water-proofing solution, if desired.

'The solutions may be used in a wide variation of concentrations, depending upon the meth-- od of application to the web, and the amount of protein material deposited on the web. I have found that in the treatment of wall papers in which the colored clay or other inert material is held on the paper by means of a sizing including a protein material, a. 10% solution is suflicient for completely water-proofing the paper in a single application, but in the case of papers Where heavier applications of sizing material are used, a greater concentration may be employed. When more dilute solutions are used, it may be necessary to use more than a single application of the water-proofing composition to produce the desired water-fastness.

The following examples illustrate how my invention has been successfully applied to the water-proofing of wall paper, but it will be understood that it is not intended to limit this invention to the specific examples given, since the proportions and ingredients may be changed materially. It is also possible toobtain excellent results by mixtures of the compositions specified in the various examples:

Example 1 100 parts of water, 10 parts of technical aluminum sulfate, 2 parts to 5 parts of sodium acetate, and 2 parts of borax are dissolved to produce a solution having a pH value of approximately 4.1, when using 5 parts sodium acetate, and when applied to wall paper printed with ordinary colors and a protein sizing composition, produce exceptional water-fastness. In this case, the sodium acetate is primarily used to raise the pH value of the solution and in a small degree acts as an accelerator in conjunction with the borax. The use of borax or other accelerating agent is of great importance in this composition, since if the borax is omitted, the degree of water-fastness is materially reduced;

Example 2 10 parts of aluminum chloride (crystal) are dissolved in 100 parts of water and 4 to 5 parts of soda ash are added. This produces a solution having a pH of about 4.2, and when applied to a protein sizing material, very effectively makes the same water-fast.

Example 3 100 parts of water, 10 parts of aluminum chloride and 5 parts of borax are mixed, resulting in aosolution having a pH of about'3.7. If, in place of 5 parts of borax, 2 parts of borax and 2 /2 parts of soda ash are used, the pH is raised to about 3.9 to 4.

Example 4 In 100 parts of water, 10 parts of aluminum sulfate, 4 parts of borax and 2 parts of soda ash are dissolved. The solution has a pH of 4.0 and referred to are by weight. Aluminum chloride may be substituted for aluminum sulfate in Ex-- amples 1 and 4,- inwhich case, the pH value of theresulting solution will tend to be slightly more acid, due to the greater acidity of aluminum chloride. In Examples 2 and 3, crystalline aluminum chloride is used, but the anhydrous aluminum chloride may be used, if proper care is taken, in which case the quantity to be used may be reduced so that approximately the same quantity oi A1Cla.6H2O will be present in the final solution.

In using relatively dilute solutions of the water-prooflng composition as is necessary for wator-proofing wall paper and the like, in which a relatively ,thin film oi proteinadhesive ma-' terial is used, the water-proofing composition has very little effect upon'the texture of the wall paper. If, however, larger quantities oi the aluminum salts are applied to a web of material, as may be necessary if the web is thickly coated with protein adhesive material, the web may become stiflfened somewhat by the water-proofing composition. This tendency, however, canreadily be overcome by using a suitable plasticizer in conjunction with the sizing composition, such as glycerine, Turkey red oil, and the various glycols. Glycerine and diethylene glycol may be used in conjunction with the water-proofing solutions to insure a desirable softness and pliability of the surface. I

In the carrying out 0! my process, the fllm of material containing a protein adhesive substance is applied in the usual manner to a web of paper, fabric or other material. This web may then be treated with my water-proofing composition, either immediately while the film is still, wet, or alter the same has been dried. In'the use of my process in connection with wall paper, the printingot the paper may be carried on bymeans of "pulp colors and a suitable sizing composition containing glue, casein, or other protein adhesivematerial dissolved therein. My improved water-.prooilng composition may be applied to the printed paper in any suitable manner, either immediately after the printing of the paper, or after the paper has been dried. The solution may be sprayed upon the printed surface of the paper or may be applied thereto by means of rollers. The paper may be completely immersed in the solution, or the solution'may 3 be applied to the back of the paper, in which case it may be desirable to include in my solution a penetrant or wetting agent to expedite the passage of the solution through the paper. The' paper can then be immediately dried, since the aluminum salt of, the water-proofing composition penetrates very rapidly into the film structure of protein, clay and/or pulp colors, so that the paper immediately after the application of my "water-proofing composition can be dried. During the drying, the water-proofing composition deposits a basic alumina salt, which makes the adhesive substantially insoluble in water, so that the color which is held on the paper by the adhesive is not removed by wiping the paper with a damp cloth or the like.

I claim as my invention:

1. A composition for making water-fast a film containing protein adhesive material and applied to a web, said composition including the reaction product of said protein material formed with a; water solution of an aluminum salt of an inorganic acid, said solution including an alkali substance for reducing the acidity of the solution to a pH of 3.5 to 4.6,'and an accelerating agent"- selected from a group consisting of the followfonated phenols.

, 2. A composition for water-proofing an adhesive fllm containing protein, saidsolution including 50 to 200 parts of water having dissolved therein approximately 10 parts of aluminum sulfate, 2 to 5 parts of sodium acetate and two parts oi borax.

3. A composition for water-proofing an adhesive film containing protein, said solution including 50 to 200 parts of water having dissolved therein approximately 10 parts 0! aluminum chloride, and 4 to 5 parts of soda ash.

4. A composition for water-proofing anadhesive film containing protein, said solution including 50 to 200 parts of water having dissolved therein approximately 10 parts or aluminum 1 taining an accelerator selected from a group including borax, sodium, ammonium or potassium acetates, oxalates and tartrates and sulfonated phenols.

, JOHN R. HUBBARD. 

